How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Kevin Your Own Question
Kevin
Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3338
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
71008832
Type Your Electrical Question Here...
Kevin is online now
A new question is answered every 9 seconds

I thought that one of my smoke alarms was dead, so I bought

Customer Question

Hi. I thought that one of my smoke alarms was dead, so I bought and installed a new one. Still no power to the alarm. Then I thought it might be because the two of them are, in phase..or joined? The red/orange wire was connected. Then I tested the current from the wires with a multimeter. No juice. Other ceiling lights on the same breaker are working. Could the previous owner, disconnected power to these outlets? And how do I fix it?
Regards,
Tammy
Submitted: 7 months ago.
Category: Electrical
Expert:  Kevin replied 7 months ago.

Hello and welcome to Just Answer. My name is ***** ***** I will be happy to assist you with your electrical question.

1) If no 120 volts at the smoke box, then either an open hot or open neutral or a loose splice on either wire at an upstream box.

2) What are the wire colors on the smoke unit?

3) How many and what are the house wire colors in the ceiling box?

Customer: replied 7 months ago.
could be at an upstream box.White, black, red.White, black red...and there are four cables coming into the box, three are white, black open copper, and one is white black red.
Expert:  Kevin replied 7 months ago.

Thanks for the replies.

1) One of the cables should be for the circuit feed. It is possible that there is a loose wire splice or termination upstream of the smoke ceiling box.

2) Possibly a faulty wire splice. Re-check the wire nut splices and make sure the wires are twisted together.

3) The smoke black is the hot, the white is the neutral and the red is the inter-communication wire.

4) The black, white and red cable is most likely being used to connect to other downstream smokes. The red wire in that cable is probably used as the inter-communication cable. Therefore, power to the box must be fed from one of the other 3 cables.

Customer: replied 7 months ago.
On the same circuit breaker that contains the two dead junction boxes to the smoke alarms are a ceiling fan, and three ceiling lights...the fan and the lights work, only the smoke alarm boxes are dead, and both of then have no current when I turn the breaker on. Where could these be disconnected? I twisted all of the wire nuts. And I tried wiring the new alarm with out the red wire to see if it worked independantly of the the kitchen one. I suspect that the previous owner has disconnected them some how. Why else would other fixtures work perfectly?
Expert:  Kevin replied 7 months ago.

Thanks for the replies.

1) All depends upon where the smoke alarm power originated from. Definately originated from an upstream box.

The originating box could be wall receptacle or a wall switch box or another ceiling lighting box or even a junction box.

2) In cases such as this and not knowing where the smoke alarm power originated from, all 4 cables will need to be accounted for. I typically use a toner and a tracer probe to locate the origin of cables if I don't know the location. Shown in the link below is a toner and probe that can be used to trace unidentified wires.

http://www.homedepot.com/p/Ideal-TRACETone-Cable-Wire-Tester-and-Locator-62-140/100598687

Expert:  Kevin replied 7 months ago.

1) Important Note: If using a toner/probe or a continuity tester, the branch circuit breaker must be in the OFF position and a multi-meter needs to confirm that voltage does not exist on any wires. If voltage is present on wires, the toner/probe or continuity testing device will be destroyed.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks...............Kevin:)

Expert:  Kevin replied 7 months ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks...............Kevin:)

Expert:  Kevin replied 7 months ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks................Kevin:)

Customer: replied 7 months ago.
Hi,
Sorry for not getting back, I am looking for a tone tester to try and map out this circuit. I will know more by Friday.
Expert:  Kevin replied 7 months ago.

OK, very good.

Related Electrical Questions